Most any 12v 'power brick' should work just fine. The brick just needs to generate enough miliiamps (check the bricks rating), to meet the combined needs of all the fans to be hooked up to it. The fans don't really drain all that much. I am a bit of a packrat and keep some old power adapters for things such as network hubs, kids toy's rechargers, etc lying around. You can hook the up any way you prefer. I usually just cut off the connector at the end of the wire, strip it back, and solder (or use a twist on cap) and some electrical tape to secure it to the pos/neg leads on the fan. You can usually tell what is positive and negative by the color of the wires... but a volt meter can come in useful if unsure. The fan should be hooked up properly.. positive and negative to make sure the fan spins in the correct direction (as I recall).
If you want to get a tad more fancy or practical, you can wire an on/off switch or variable speed switch.
I have my power brick plugged into my Apex EB8. I then set the desired fan speed with a variable speed switch between the power brick and the fan(s). When the tank temp hits a certain level, the fan(s) turn on. I usually run my fan full speed as it isn't that loud. But if you have a lot of fans, you can turn them down a bit to keep the tank from sounding like a wind tunnel.
Its a lot easier to do than it sounds.. and you do not 'need' to solder. Twist on wire caps and electrical tape works just fine. Shrink tube is also handy. Splice, slide over the shrink tube, twist the wires together. Slide the shrink tube over the connection. Use a lighter to heat the shrink tube. It then makes a nice airtight seal.
If it helps maybe I can take a few pics of the one I made and post them. My variable speed switch was actually commandeered from an old AMD computer processor fan.
